Hey everyone,

So I had this problem that was driving me nuts. I've got 1000+ plugins on my Mac, and they're eating up a ridiculous amount of space on my boot drive.

Why? Because every plugin on Mac is now a "Universal Binary" – meaning it contains code for both Intel Macs AND Apple Silicon Macs in the same file. Literally double the size they need to be.

If you're on Apple Silicon (M1/M2/M3/M4), you're no longer using that Intel code. Back in the day, some of us ran Intel plugins through Rosetta, but now everything is fully native – all the major plugins have been ported to ARM. And with Apple planning to drop Rosetta support soon anyway, that Intel code is just sitting there taking up space.

So I built a simple app to recover that space. You just pick which plugin folders you want to process, select which formats (AAX, VST, VST3, AU), and hit go. Takes a few minutes and boom – half your plugins' size gone.

There is a simulation mode (estimate) that will only run an estimation and tell you how much GB you can save. Nothing will be modified in that mode, so it's worth trying it . A new option may handle some tricks for plugins with weird permissions or attributes.

Download the app here (current version 1.6):
https://www.avelio.tech/unfatten

Important stuff:

- This is beta ! it works great for me and for others, but your mileage may vary.
- Backup your plugins folder first – just in case something weird happens with a specific plugin
- The only plugins I've had issues with are Sonnox (they crash after stripping), so I just exclude those
- Some plugins are installed with weird permissions (root owner or immutable flags) – the app will do its best to process those, and guide you on how to fix issues on them.
- When you update plugins, they'll come back as Universal binaries, so just run it again. I do it monthly

If you're on an Intel Mac:

You can use this to strip out the ARM code instead and save the same amount of space. Just be aware that if you upgrade to an Apple Silicon Mac down the road, you'll need to reinstall all your plugins since they won't have the ARM code anymore.

That's why I personally wouldn't recommend it for Intel users unless you know what you are doing – the option is there if you desperately need the space.

If estimation is working but processing doesnt free space partially or totally
You probably have a permission or attribute issues on those files. Click the fix permission buttons, try again, and follow the instructions if Unfatten need your help to solve those issues.

The deal:

This is free, no strings attached. Use at your own risk, no warranties given. If you've got a smaller SSD and/or you're constantly juggling space, this might help you and save you time.

Let me know if you try it and how much space you recover.
Happy to answer questions!

 

I’ll have to reinstall all my plugins when I upgrade to apple silicon anyway, this might be able to reach where clean my Mac doesn’t, it could remove unnecessary binaries but I don’t know if it works for plugins like it does for applications

 

"Hundreds of GB" is a complete overstatement. All you are doing is using terminal utilities like Lipo, ditto, and file to strip either ARM or Intel slices to create what we call a "skinny" Mach-O binary. Hence the name Lipo.

You are looking at a 50% reduction in size to remove one slice and keep the other. Right now I have 700 plugins installed. They are taking up 19gb of space. So I would save roughly 9.5gb by stripping every one of them, if they were all fat binaries to begin with.

Nothing about this is going to save anyone hundreds of gb by stripping plugins. When people take this "advice" and then come back with the problems they will invariably run into, are you going to fix it for them?

 

some people on other forums are freeing up between 20-40Gb ! And one pro guy using all 4 format (VST, VST3, AAX, Components) has indeed recovered over 200GB (around 50Gb per format), but I agree that's rare case

 

Windows installers like that allow you to select plugin format such as vst2,vst3,aax, and so on. But it will install one plugin for each format into the correct locations for use. Mac U2B plugins contain both architecture "slices" inside the same 1 plugin file.

So no, this isn't new; because it isn't even new for Mac. Plugins have been released as U2B since they rolled out the M1 Apple Silicon ARM processors in 2020.

If by "Pro" you mean having your "2000 plugins" really only be 500 taking up 4 times the space, then sure. It's a Mac, so you do not need 4 plugin formats on the system disk just waiting for someone to send files in every DAW and plugin format they can think of. A "pro" would just have them sitting on an external disk and just drag them back in like 5 seconds.

Spoiler

What “both architectures in one plugin file” means on macOS
On macOS, “Universal 2” or “Fat” binaries let one executable (or library) embed multiple architectures (e.g. x86_64 + ARM64) so it can run natively on different hardware without needing separate files.
Developers commonly distribute a single plugin or app bundle that “just works” on either architecture.

Why Windows doesn’t typically do that (for 32/64-bit)
Windows does support a form of “fat binary” in certain newer contexts (notably for ARM/ARM64/EC) via extended PE formats (e.g. Arm64X) Wikipedia. But for the classic case of x86 (32-bit) + x64 (64-bit), combining both into one DLL is not standard or widely supported.

Some reasons:

• A 64-bit process can’t load a 32-bit DLL, and vice versa. They are incompatible at runtime. JUCE+1
  
  
• Plugin architectures and host applications expect “matching bitness” (32-bit plugin into 32-bit host, 64-bit plugin into 64-bit host).
  
  
• Many plugin formats on Windows (like VST2) are simply a single DLL, so embedding both would break expectations.

How Windows plugins do support multiple architectures “in one bundle”
While you won’t typically find one DLL with both 32- and 64-bit code, plugin bundles or packaging conventions often include both versions under a single umbrella. Some examples:

• VST3 “bundle” format
  The VST3 standard supports a “bundle-like” folder where different architectures are kept in subfolders. For example, inside MyPlugin.vst3/Contents/ you might have:
  • x86-win/MyPlugin.vst3 (32-bit DLL)
    
    
  • x86_64-win/MyPlugin.vst3 (64-bit DLL)
    
    
  • (And for Windows-on-ARM, arm64EC or Arm64) Steinberg Media
    So effectively, one “plugin package” contains both architectures, and the host picks the right one.
• AAX bundles on Windows
  Some plugin frameworks like AAX allow bundling separate DLLs under a shared plugin “bundle” so that both 32- and 64-bit variant DLLs are shipped together. But internally they remain separate files. JUCE

Thus you see a hybrid approach: you get “one plugin package” from the user’s perspective, but it internally contains separate architecture-specific binaries.

Summary

• Windows does not generally support a single binary that contains both x86 and x64 code (for classic plugins/interfaces).
  
  
• For newer Windows/ARM scenarios, Microsoft is developing and using formats like Arm64X which can embed multiple architectures. Wikipedia
  
  
• In practice, plugin vendors often ship a bundle that contains separate 32- and 64-bit binaries under one package (e.g. VST3 bundles, AAX bundles).

 

Yeah who even has all formats other than a professional studio workstation? Especially one that’s made for public use or to work for clients? Aside from those who have no money cause they spent it all getting cursed by pro tools there’s no need for aax plugins, I only use AU/VST3 aside from the vst2 plugins that only have that option available instead of 3, and it’s even more streamlined in windows, just using vst3 whenever possible! I wouldn’t be surprised if I could get another 10 gigabytes out of my MacBook cause I recently cleaned out some plugins anyway a month or two ago and it can help with whatever I can’t get rid of or gotta keep

 

The real point on mac is that all plugins are installed with both Intel and Arm code, when generally you only need one of them. Meanwhile space usage is doubled

 

Just saved 14gigs on my harddrive.. thank you so much for this, what a g!!